Induction regulator block

ABSTRACT

The invention provides a manifold block for improving the efficiency of an internal combustion engine. The manifold block is arranged to be located between an inlet manifold and a cylinder head of the engine, and comprises a block of material having at least one manifold channel there through. The manifold channel has an input end and an output end, wherein the input end is connected to the inlet manifold, and the output end is connected to the cylinder. The manifold channel includes at least one injector head channel located towards its input end and adapted to receive a fuel injector. The manifold block may also incorporate one or induction regulators for improving the efficiency of fuel/air mixing in the manifold channels.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a manifold block for an internalcombustion engine and in particular a manifold block that promotesmixing of fuel and air in the engine upstream of the cylinder head,improving the efficiency, emissions profile and/or power of the engine.The block may also incorporate an induction regulator further tofacilitate fuel/air mixing.

2. Description of the Related Art

It is well known to use a fuel injector to control the fuel/air mixtureratio in an engine. Conventional fuel injection systems are generallyadapted to monitor the amount of fuel supplied to the engine, or to eachcylinder thereof, the timing and duration of each injection event beingcontrolled to provide a desirable fuel/air mixture in the cylinder.However, conventional injector systems are generally not designed tooptimize the mixing of fuel and air upstream of the cylinder(s), and thepresent invention seeks to provide a means for optimizing this aspect ofinjector systems.

WO-A-01/63107 discloses an internal combustion engine for liquidpetroleum gas or compressed natural gas and particularly an internalcombustion engine fitted with a pressure release valve operable (byelectrical or mechanical means) to open during the compression stroke ifthe pressure in the cylinder exceeds a predetermined value correspondingto the maximum desired compression ratio in the cylinder, but is heldshut during the ignition stroke. When the valve is open during thecompression stroke, excess fuel/air mixture is bled from the cylinderand passes through a one-way valve and a cryocooler to the inletmanifold where it mixes with fresh incoming air. The system may also beused in petrol/diesel engines which have been modified to use gas asfuel.

GB-A-2,390,116 discloses an intake manifold, fuel rail and mouldedinjector pack assembly for internal combustion engines havingconfigurations which result in the necessity for only a single seal atthe connection between the fuel rail and moulded injector pack assembly.

WO-A-02/25092 discloses a method and apparatus for mechanicallygasifying an atomized fuel/air mixture. This apparatus comprises ahousing in which is disposed a stator body, the inner surface of whichhas an array of pins projecting inwards therefrom. There is alsoprovided a rotor body having an array of pins projecting outwards fromthe outer surface thereof. The rotor is arranged to rotate at high speedand is located such that its pins intermesh with those of the stator. Amotor (driven by compressed air/exhaust gas/electrical motor) isprovided to drive the rotor. The housing is closed at either end savefor an inlet at one end for receiving atomised fuel from an injector,and an outlet at the other end for directing gaseous fuel into an intakemanifold/intake valves of an internal combustion engine. The fuel isgasified by way of the rotor/stator pins striking fuel droplets, therebycreating smaller droplets. In one embodiment, the “stator” may bearranged to rotate in a direction opposite to that of the rotor toincrease relative velocities between the pins.

U.S. Pat. No. 5,673,673 discloses a method and apparatus for injectinggaseous fuel at velocities of the order of Mach 1 into an air streamflowing into an intake port of an internal combustion engine. Theapparatus is mounted between the intake port of the internal combustionengine and the air intake manifold. The injection apparatus is arrangedto inject the gaseous fuel into the air stream at between Mach 0.5 andMach 1 to achieve uniform mixing of the fuel and air. Key to achievingthese high injection speeds are the effective flow areas of the injectormetering orifice (i.e. the orifice from which the gaseous fuel leavesthe injector and enters a conduit leading to a discharge orifice) andthe conduit discharge orifice. In particular, an effective flow area forthe conduit discharge orifice of between two and five times greater thanthe effective flow area of the injector metering orifice is effective inachieving these high injection speeds. A further requirement forachieving the high injection speeds is that the pressure at which thegaseous fuel is supplied is more than four times the air intake manifoldabsolute pressure.

GB-A-2,409,499 discloses a regulator with driven propeller for intake orexhaust manifolds of internal combustion engines.

U.S. Pat. No. 4,478,607 discloses a device for atomizing and dispersingfuel in a fuel/air mixture. The fuel mixer/atomizer comprises a hollowcylindrical body provided with a propeller to mix the air and fuel(driven by fuel flow) and a screen serving the dual purpose of trappingdebris and further atomizing the fuel.

U.S. Pat. No. 6,269,805 discloses a manifold spacer, which comprises anapparatus adapted to be inserted between an outlet of a carburettor andthe inlet of an intake manifold. The apparatus comprises a body memberhaving an opening therethrough, the size of which is consistent with theoutlet opening of the carburettor and the inlet of the intake manifold.Nitrous oxide and fuel manifolds span the opening and are provided witha plurality of orifices to direct spray downwards towards the inlet ofthe intake manifold.

These prior art devices each suffer from one or more of the followingdisadvantages: they are overly complex in design, giving rise toadditional cost and likelihood of mechanical failure; they are difficultto retrofit; they do not work satisfactorily in practice to improveengine performance; they do not work satisfactorily in practice todecrease engine emissions. It is an object of the present invention toprovide an induction regulator block for an internal combustion enginewhich ameliorates one or more of the aforesaid problems. In particular,it would be desirable to provide a means for retrofitting to an existingengine a device effective to improve the mixing of fuel and air suppliedto the cylinder head (or heads) thereof.

It is therefore an object of the present invention to provide a manifoldblock for an internal combustion engine for improving the efficiency,emissions profile and/or power thereof.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a manifold block forimproving the efficiency of an internal combustion engine, the blockbeing adapted to be located between an inlet manifold of the engine anda cylinder thereof, the block having at least one manifold channeltherethrough, the manifold channel having an input end and an outputend, wherein the input end communicates in use with the inlet manifoldand the output end communicates in use with the cylinder, the manifoldchannel including at least one injector head channel located towards itsinput end and adapted to receive a fuel injector, said injector headchannel being orientated with respect to the longitudinal manifoldchannel axis and/or with respect to the transverse manifold channel axisat an angle of convergence from 5° to 85° such that fuel injection intothe manifold channel impinges against the manifold channel wall andadopts, by virtue of the convergence angle, a swirling path of motionthrough the manifold channel.

In use, the manifold block of the invention is fitted between the inletmanifold and the cylinder head, thereby increasing the distance betweenthe fuel injection point and the cylinder head, and at least partlybecause of the angle of convergence of fuel injection with respect tothe manifold channel axis, is arranged to facilitate turbulent mixing ofthe injected fuel in the manifold channel. To this end, the injectorhead channel is oriented with respect to the manifold channel axis, suchthat fuel injected into the manifold channel impinges against themanifold channel wall thereby adopting a substantially swirling path ofmotion through the manifold channel. The axis of the injector headchannel and the axis of the manifold channel at the location ofinjection converge at an angle of convergence effective to facilitatesuch swirling motion. The orientation may be with respect to thelongitudinal channel axis of the manifold, or with respect to thetransverse axis thereof, or with respect to both the longitudinal axisand the transverse axis. In each case, the convergence angle may be fromabout 5° to about 85°, preferably from about 15° to about 75°, morepreferably from about 20° to about 70°, and most preferably from about20° to about 65°. A convergence angle of from about 25° to about 60° maybe especially preferred in some cases.

Although the convergence angle is important to facilitate swirlingmotion in the fuel/air mixture entering the cylinder, it is alsosignificant that the manifold block of the invention acts in use toincrease the distance between the fuel injection point and the cylinderhead, thereby allowing the fuel/air mixture space and/or time to adopt aswirling motion on entering the cylinder. In one sense this isfacilitated by the manifold block having a length, which may usefully bedefined as the manifold channel length therethrough, which is preferablymore than about 1 cm, more preferably more than about 2 cm and mostpreferably more than about 3 cm. However it will be understood that thechannel length will usefully be selected with regard to the type ofengine to which the block is to be fitted, and the preferred length ofthe channel may therefore to some extent be determined by externalfactors. In some cases channel lengths of over 5 cm may be preferred.

Another aspect to the provision of swirling space upstream of thecylinder is the point at which the fuel is injected, which is preferablytowards the upstream end of the block, thereby effectively extending thedistance between the fuel injection point and the cylinder head.

It should be stressed that the manifold channel need not necessarily bea straight and/or uniform channel, although it may be. In the case of anon-straight and/or non-uniform channel, the longitudinal axis will beunderstood to be the axis parallel to the air flow in that part of themanifold, and the transverse axis is the axis normal to the airflow. Itwill be understood that a key feature of one preferred embodiment of theinvention is that swirling motion of the fuel is initiated in themanifold channel upon injection of the fuel therein. Swirling of thefuel in the manifold channel assists the mixing of the fuel in themanifold channel and/or introduced into the manifold channel togetherwith the fuel and/or via a separate injection head in the manifoldchannel, or above it. Once the fuel has commenced its swirling motion,bends, curves and/or irregularities in the manifold channel structureneed not prevent continuance of such swirling motion. Preferably,however, the contour of the manifold channel is effective to promote,maintain, facilitate, or at least not unacceptably compromise, swirlingmotion of the fuel therein.

The injector head channel injects fuel and/or a fuel/air mixture intothe manifold channel in operation of the invention. There may be one ormore such injector head channel in each manifold channel of a manifoldblock according to the invention. Preferably each injector head channelis situated towards the upstream end of the manifold channel in use ofthe invention. In this way, the distance between the injector head andthe cylinder head of the engine is maximized. Means may also be providedto alter the position and/or orientation of the injector head channel tocontrol the direction of the injected fuel in response to the particularrequirements of the engine.

In some engines, fuel and air are injected separately, and it may bedesirable in this case to provide the manifold block with separatedinjection heads for fuel and air injection. Alternatively, or as well,it may be convenient in some cases to provide a first manifold blockwith a fuel injection head therein, and a second manifold block in fluidcommunication with the first via their respective manifold channels withan air injection head therein.

The manifold block of the invention may be used in petrol-drivenengines, diesel-driven engines, and engines which are fuelled by othertypes of fuel (bio fuels for example), or combinations thereof. Suchengines may be found, for example, in cars, lorries, trucks, wagons,off-road vehicles, tanks, tractors, motorbikes, aircraft, seacraft, andin agricultural/horticultural vehicles and tools. Moreover, the manifoldblock may be fitted to a single cylinder engine, or to a multi-pointengine. In a multi-point engine the manifold block will generallycomprise a single block of suitable material with a plurality ofmanifold channels therein, the number of manifold channels correspondingwith the number of cylinder heads in the engine. Preferably the outletends of each manifold channel are machined to match in contour the inletport of the engine cylinder head. Thus, the manifold channel may becylindrical but may be any suitable shape.

The manifold block of the invention is effective to improve thecombustion efficiency of an internal combustion engine by providingsufficient distance between the fuel injector and the combustioncylinder of the engine, so that the injected fuel has sufficientopportunity to mix with the air, through turbulent mixing, prior tocombustion, thereby improving fuel vaporisation and atomisation.Moreover, by improving combustion efficiency in this way, fuelconsumption and unwanted exhaust emissions can be reduced.

In order to assist turbulent mixing of fuel and air through the manifoldchannel, the manifold channel may, in a preferred embodiment of theinvention, be provided with an induction regulator therein, of the typedescribed in PCT/GB02/01831, or in UK 0428194.5, or of another type ashereinafter described. Alternatively, or as well, such an inductionregulator may be mounted in the cylinder head of the engine in use ofthe manifold block of the invention.

When fitted, the induction regulator may comprise one or more of thefollowing elements:

-   -   A perforated element, such as a mesh or perforated plate, for        example, mounted in the manifold channel, or beneath it.    -   A propeller mounted in the manifold channel, or beneath it.    -   A deflector grid mounted in the manifold channel, or beneath it.

The purpose of each of these elements, alone or in combination, is tocause the injected fuel in the manifold chamber (or the injectedfuel/air mixture) to flow turbulently into the cylinder head downstreamof the manifold channel.

When a perforated element is present, this may be mounted in or beneaththe manifold channel to correspond in size with the cross-sectional sizeof the channel or, alternatively, may be sized to leave a peripheral gapbetween the manifold channel and the perforated element. The perforatedelement is preferably mounted at a tilt within the inlet manifold, orbeneath it. The angle of the tilt, when present, is preferably fromabout 1° to about 45°, more preferably from about 2° to about 35°, mostpreferably from about 5° to about 25° from the horizontal, thehorizontal being the arrangement in which the plane of the perforatedelement is normal to the longitudinal axis of the manifold channel atthe location of the perforated plate therein or, if the perforated plateis mounted below the manifold channel, the longitudinal axis of themanifold channel at the outlet thereof extended in a straight line.

The perforated element is capable of allowing the passage of a fuel/airmixture there through, from the manifold channel upstream end in theregion of the fuel injector to the manifold channel downstream end inthe region of the cylinder head, and preferably of causing such passingmaterial to mix turbulently. Means may be provided for mounting theperforated element in the manifold channel, or beneath it.

It is possible to provide more than one perforated element in themanifold channel, or beneath it. A number of configurations ofperforated elements can be utilised, and such configurations aredependant upon the size and curvature of a specific manifold. In oneembodiment, a first perforated element is disposed towards the upstreamend of the manifold channel, and a second perforated element is disposedtowards the downstream end of the channel, or beneath the channel.

Each perforated element may be rotatable about a shaft in the manifoldchannel further to enhance turbulent mixing of fuel/air passingtherethrough. Furthermore, each perforated element may be operablebetween a closed position arranged to allow passage of fuel/air mixturethrough the perforations, and an open position arranged to allow passageof the fuel/air mixture bypassing the perforations.

The propeller, when present, may be freely rotatable, or may be drivenby a motor. The propeller may be mounted in the manifold channel, orbeneath it, and may be mounted at an angle with respect to thelongitudinal axis of the manifold channel. Preferably the angle of thetilt, when present, is from about 0.6 to about 60 degrees, morepreferably from about 5° to about 50°, most preferably from about 15° toabout 40°. In one embodiment of the invention, the propeller isdeployable in forward or reverse mode, and may therefore be rotatable(whether, freely, under the influence of fuel/air impingingthereagainst, or driven by a motor) in both clockwise and anti-clockwisedirections. Preferably, the propeller is rotatable in the directionwhich maximises turbulent mixing of the fuel/air mixture in the manifoldchannel, and/or in which the fuel/air mixture upstream of the propellerin use of the invention is pulled downstream by the propeller blades inthe most effective manner.

In one preferred embodiment of the invention, the manifold channel isprovided (therein or therebelow) with a perforated element and, mountedbeneath the perforated element, a driven propeller.

Preferably, the propeller has a longitudinal pin defining a rotationaxis, and at least one blade attached to the pin. At least one blade ispreferably attached to the pin by means of an elongated blade root whichsubstantially follows the longitudinal axis of the pin. Preferably, theblade root follows the longitudinal axis of the pin in an at leastpartial helical manner. The length of the blade root may be greater thanthe distance between the blade tip and the pin. The length of the bladeroot may be substantially equal to the blade length. The term “bladeroot” should be taken to mean the area of the blade where the bladeattaches to the propeller boss/pin. The blade may be substantiallycurved in shape and may have a substantially smoothly curving bladeedge. Preferably the blade has a shape substantially of a semi-circle,an ellipse, a part-ellipse, a teardrop, a half-tear drop, a bell curve,a half-bell curve, a rectangle, a square, a triangle, or derivativesthereof. The blade may be wider towards one end of the blade root.

The function of the propeller is preferably to be effective to pullfluid material from a region upstream of the propeller to a regiondownstream of the propeller, and additionally to cause turbulent fluidflow in the region downstream thereof. In this case the propeller ispreferably driven by a suitable motor using if appropriate a gearingmechanism or pulley. A single motor may drive a plurality of suchpropellers but it is also possible to provide separate motors for eachpropeller, or some of them.

Each propeller may be mounted in the manifold channel, or beneath it, byany suitable means such as for example one or more supporting straps orbraces. However, the supporting straps need not be present, and thepropeller may be mounted in the manifold channel in other ways.Preferably each propeller is mounted in a supporting framework with, ifappropriate, suitable electrical connections for driving the propellerand data transfer lines for controlling the motion of the propeller, thesupporting framework being securely attached to the manifold block.

Each blade of the propeller may be attached to the pin at differentpositions so that the blades may have a “staggered” appearance. Eachblade may also be of a different or similar size, and indeed each blademay have a different shape from any other blade. The propeller ispreferably sized to leave a small (generally a few mm) peripheral gapbetween the path swept by the propeller blades in use and the manifoldchannel wall inside or beneath which the propeller is mounted. When thepropeller is used in combination with a perforated plate, the propelleris preferably sized so that the path swept by the propeller blades inuse roughly corresponds in size with the perimeter/circumference of theperforated plate.

It is also possible to provide a plurality of propellers in any onemanifold channel. These may be spaced along the manifold channel length,or part of it.

The deflector grid, when present may comprise one or more flangesprotruding into the manifold channel, or into the path defined by anextension of the manifold channel when the grid is mounted beneath thechannel. Any such flange is preferably arranged such that fuel/airmixture passing through the manifold channel impinges against anupstream surface of the flange and is thereby forced to flow withadditional turbulence around the flange. More than one flange may beprovided, and these may conveniently be arranged around thecircumference of an insert member which may be fitted inside themanifold channel, or beneath it.

The manifold block of the invention may be used in combination with anyone or more of the perforated plate, propeller and deflector grid. Whenpresent each of these devices form part of an induction regulator usedin combination with the manifold block of the invention. Furthermore,means may be provided for heating the manifold block, the inductionregulator, or any part thereof, in use of the invention in order tomaximise fuel efficiency during cold engine start-up. When the inductionregulator, or any part of it, is mounted beneath the manifold channel,it may protrude into the cylinder head in use of the invention.

The manifold block of the invention provides the advantage that itserves to separate the fuel injection poured from the cylinder headthereby to enhance fuel/air mixing in passage from the fuel injector tothe cylinder head, optionally in conjunction with an induction regulatoras herein before described. The manifold block may be deployed in anew-build engine, or may be retro fitted to an existing engine. Whilstthe manifold block is for insertion between the cylinder head and theinlet manifold, in a new-build engine the block need not be an entirelyseparate component from the inlet manifold, the inlet manifold of thenew build engine may instead be designed to incorporate the manifoldblock of the invention. Effectively in this case the block becomes partof the inlet manifold.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described further hereinafter, by way of example only,with reference to the accompanying drawings, in which:

FIG. 1 schematically shows a perspective view of a conventional manifoldand cylinder head:

FIG. 2 schematically shows a plan view of a manifold block with injectorchannels according to the present invention:

FIG. 3 schematically shows a perspective view of the manifold blockshown in FIG. 2 when inserted in the manifold and cylinder headarrangement of FIG. 1:

FIG. 4 a schematically shows a top view of a manifold block withinduction regulator according to the present invention:

FIG. 4 b schematically shows a further view of the FIG. 4 a blockaccording to the present invention:

FIG. 5 schematically shows a perspective side view of the block of FIGS.2 and 4 a and 4 b inserted in the manifold and cylinder head arrangementof FIG. 1:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In overview the present invention provides for a manifold head forattachment to an internal combustion engine. The block includes channelsto allow the passage of fuel from an injector head and air from an airinlet manifold to a combustion cylinder of the engine. Each channel hasan entrance end and an exit end. The number of channels generallycorresponds to the number of cylinders in a particular engine.

Referring to FIG. 1, the conventional manifold head 100 may consist of amanifold head 102, having a plurality of manifold channels 104, 106,108, 110 formed there through. The manifold head engages the cylinderhead 103, and the manifold intake channels 112, 114, 116, 118 feed airinto the cylinders 120, 122, 124, 126 via manifold channels 104, 106,108, 110. Fuel injection occurs at the cylinder head in the prior artarrangement of FIG. 1 as indicated by 113, 115, 117, 119.

Air is drawn up into the manifold channel 112 (for ease of explanationonly one set of description numerals are referred to) of the manifoldhead 102, passed along the manifold channel 104, into the cylinderchannel 120, where fuel is injected into the cylinder channel 120 via aninjector head 113. The fuel/air mixture is ignited in the combustioncylinder channel 120.

Referring to FIG. 2 the block 140 according to the present inventionincludes a plurality of injector channels 132, 134, 136, 138, each ofwhich are adapted to receive a fuel injector head as schematicallyrepresented in FIG. 2. The injector channels are arranged so that fuelinjector heads 140, 142, 144, 146 can be inserted through the block atan angle (for example about 45 degrees) into the manifold channels witha swirling motion. The injector channels 132, 134, 136, 138 are arrangedtowards the top of the manifold block so that they are in spacedseparation from the cylinder heads of the engine when deployed.Advantageously the block can also be attached to the engine duringmanufacture, or alternatively can be attached as a retro-fit devicefollowing manufacture.

Typically the block may measure about 35 cm in length and 9 cm in widthand height, and may have a substantially rectangular in shape, althoughother shapes may also be used. Generally the height of the block andthus the length of each manifold channel must be adequate to providesufficient distance between the injector head and the combustioncylinder so as to allow for mixing of the fuel/air mixture. However thedimensions of the block can vary in size, dependant on the size andapplication of the engine, and also space available in the enginecompartment. The dimensions and relative positions of the standardmanifold channels are dependant on the positions of the inlet manifolds112, 114, 116, 118 to the cylinders 120, 122, 124, 126 of the engine130. The conventional manifold block example illustrates a 4-cylinderengine; however, conventional manifold blocks may have any number ofcylinders, including any arrangement of those cylinders, for exampleso-called “V” or “in-line” arrangements.

Block 1 140 may incorporate any number of injector channels, and indeedit is possible to facilitate multipoint injection whereby each manifoldchannel can incorporate multiple fuel injectors. In this case at leastone, but preferably all of the injector head channels should be mountedat a convergence angle with respect to the manifold channel. Thedimensions of the injector channels are dependant on the size of theinjector heads used, and also on the engine size and space available inthe engine compartment.

Referring to FIG. 3 the manifold block 140 according to the presentinvention is shown incorporated in the engine head arrangement. Theblock 140 can be formed of a single piece of material, and can bemanufactured from material, for example plastic, metal or ceramic, ascan be understood by those skilled in the art. For ease of reference,only one injector 132 is shown in FIG. 3.

In the preferred embodiment of FIG. 3 (and with reference only to one ofthe air intakes), air is drawn up into the manifold channel 118 andpasses along the manifold channel 110, into block 140, where fuel isinjected at a convergence angle from the injector head 132 therebyproviding optimised swirling of the fuel/air mixture entering thecylinder head channel 126. The distance from the fuel injector 132 tothe exit end of block 140 allows for substantial mixing of the fuel/airmixture prior to entrance into the cylinder head 103.

As schematically represented in FIGS. 4 a and 4 b, a second blockextending manifold channels 104, 106, 108, 110 can further incorporatean induction regulator 202, 204, 206, 208. The induction regulators aresituated in use downstream of the injector channels and in the depictedarrangement will be situated before the exit end of the manifoldchannel. However, in other embodiments the induction regulator may beprovided in the cylinder head channel.

Each induction regulator in this particular embodiment comprises aperforated element, which may be formed of a wire mesh, gauze or anyperforated material. The perforated element is preferably angled between13 to 25 degrees with respect to the horizontal, for example at about 17degrees. The perforated element may extend across the circumference ofthe manifold channel, providing no gap around the circumference of theperforated element. Alternatively, there may be a small gap around thecircumference of the perforated element separating it from the walls ofthe manifold channel. Each perforated element can be fixed within itsrespective manifold channel by any suitable supporting number.

FIG. 4 b illustrates the underside of the manifold block, as viewedtowards the exit end of the manifold channel. Optionally the inductionregulator can also include a propeller element 210, 212, 214, 216. Inthis embodiment, the propeller elements are situated down stream of theperforated element and are mounted centrally using a supporting framewithin each manifold channel, so that each can rotate around a spindlemounted in the manifold channel at an angle (from about 0.6 to about 60degrees with respect to the longitudinal axis of the manifold channel,for example).

The propellers can include a plurality of blades that are angled to thecentral axis of the propeller. The propellers have dimensions thatsubstantially match those of the manifold channels, whilst allowing thepropellers to rotate within each manifold channel. The propellers can beformed from any appropriate material, such as metal, ceramic or plastic.The shape can be an appropriate shape, such as elliptical, tear drop,bell, curve, triangular, rectangular or any variation thereof.

Each propeller element can be arranged so that it is free to rotateunder the influence of the force applied by the fuel/air mix flowingpast it. However, the block can further incorporate a plurality ofapertures 218, 220, 222, 224, each aperture adapted to receive anelectric motor 226, 228, 230, 232 which is in turn adapted to rotate thepropellers independently of the force applied by the fuel/air mixture.The number of motors used depends on the size of the engine, and thenumber used generally corresponds to the number of cylinders in theengine in question. Alternatively, a single motor can be used to driveeach propeller using an arrangement of gears or pulleys.

The perforated element and the propeller element can be heated using anelectrical heating means (not illustrated) which can be powered by anyappropriate means.

The manifold block 1 of FIG. 2 of the present invention can utilise anycombination of perforated element and propeller element of block 2 FIGS.4 a and 4 b, such that either the propeller or the perforated elementcan be used independently of each other. Also, the perforated elementand the propeller can be arranged in any order, either upstream ordownstream of one another.

Referring to FIG. 5 the manifold block 100 may be formed of 3 parts 100,(block 1) 140 and (block 2) 150.

In a preferred embodiment of FIG. 5, air is drawn up into the manifoldchannel 112 and passes along the manifold channel 104, into the block 1channel 140, where fuel is injected at an optimal angle from theinjector head 132 into block 1 140 whereby the fuel/air mixture adopts aswirling path of motion. The length of the channel allows the fuel/airmixture to substantially mix prior to entering block 2 150. The fuel/airmixture passes through the induction regulator 202, consisting of aperforated element, causing further mixing of the fuel/air mixtureenhanced by the propeller located directly beneath the perforatedelement. The fuel/air mixture is ignited in the combustion cylinderchannel 120 and passes out the cylinder channel exit end.

It should be appreciated that whilst the fuel injection block 1 140, andinduction regulator block 2 150 are depicted as separate entities, theymay both be incorporated in a single block.

The block can be fitted to any type of engine, whether petrol or dieselor other fuel, and can be used in conjunction with direct or indirectinjection engines.

EXAMPLES

A Ford Focus 1.6 engine was tested to ascertain the emissions and torqueof an engine incorporating the manifold block of the present inventioninserted between a conventional manifold and a conventional cylinderhead. These tests sought to identify change in emissions, BHP and torquewhich occurred when different sized blocks in accordance with theinvention were fitted on the vehicle.

In order to fit the new block the conventional manifold, fuel rail, andinjector were first removed, exposing the cylinder head. The block ofthe invention was then fitted on the cylinder head. For the purpose ofthese experiments it was in some cases found necessary to secure agasket between the cylinder head and the block to make the connectionairtight. In this case the gasket was fitted to the underside of themanifold block. The manifold block is then carefully placed on top ofthe cylinder head and the original inlet manifold is then fitted on topof the manifold block, again if necessary with the aid of a gasket. Theoriginal injector holes are plugged and made air tight. The fuel railand injector are inserted into the injector head channels of themanifold block at a convergence angle. The fuel rail and injector mayneed altering depending on the size of the manifold block that isinserted.

Several tests were run between idle, 35, 50 and 70 miles per hour atvarious time intervals, post cat and pre cat emissions were thenmeasured.

Emissions analysis was conducted using a Sun Modular 4 gas analyser, andSun Ram 12 rolling road was used to measure power and torque.

Table 1 shows CO₂ emission data from three manifold block formationsnamely; block, block ML 1.T, and block ML 1.T and ML 0.5, when insertedbetween a conventional manifold and cylinder head, to a conventionalmanifold and cylinder head, wherein the term block refers to themanifold block of the present invention.

TABLE 1 Speed MPH CO2 Emissions Block On 70 6.92 50 13.7 35 13.7 idle12.8 Block Off 70 8.3 50 13.57 35 13.6 idle 12.63 Difference % 70 16.650 −1 35 −0.7 idle −1.3 Block ML 1.T Block On 70 7.58 50 15.07 35 15.2idle 15.33 Block ML 1.T Block Off 70 8.32 50 15.53 35 15.57 idle 15.57Difference % 70 8.9 50 3 35 2.4 idle 1.5 Block ML 1.T and 70 7.91 ML 0.5Block On 50 15.13 35 15.2 idle 15.3 Block ML 1.T and 70 8.32 ML 0.5Block Off 50 15.53 35 15.57 idle 15.57 Difference % 70 4.8 50 2.6 35 2.4idle 1.7

Table 2 shows hydrocarbon (HC) emission, CO₂ emission, and O₂ level datafrom a single manifold block formation namely; block ML 1.T, with ablock present, inserted between a conventional manifold and cylinderhead, to the same, with the exception of no block being present.Demonstrating the insertion of the manifold block of the presentinvention provides improved engine efficiency and reduced CO₂ emission,in comparison to a standard engine.

TABLE 2 Detailed Test Speed MPH HC CO2 O2 Block ML 1.T Block On 70 1838.51 0 50 137.3 14.43 0.28 35 169.7 14.37 0.36 idle 330.3 13.43 1.57Block ML 1.T Block Off 70 249 8.65 0 50 167 14.63 0.23 35 197 14.47 0.42idle 394 13.5 1.71 Difference % 70 26.4 1.6 50 17.9 1.4 35 13.7 0.7 idle16.2 0.5

Table 3 shows torque (ft·lb) measured at 500 RPM intervals between 1500and 4500, following the insertion of the manifold block of the presentinvention, between a conventional manifold and cylinder head, and to thesame, with the exception of no block being present. The insertedmanifold block had a length of either, 102 mm, 64 mm, or 77 mm.Demonstrating the more preferable form of the invention was providedwhen the length of the manifold block was 64 mm, whereby providingoverall maximum torque for the integers of RPM.

TABLE 3 No 102 mm 64 mm 77 mm Block Block Block Block RPM (ft · lb) (ft· lb) (ft · lb) (ft · lb) 1500 55.7 62.7 63.7 55.7 2000 70.1 73.5 81.983.2 2500 80.3 81.1 88.0 88.9 3000 87.7 81.9 87.2 87.7 3500 87.5 91.993.6 91.2 4000 93.1 94.8 93.7 94.3 4500 90.3 94.8 97.0 96.2

These results demonstrate that the incorporation of the manifold blockof the invention into an engine can improve engine efficiency, emissionsprofile and/or power.

1. A manifold block for improving efficiency of an internal combustionengine, the block being adapted to be located between an inlet manifoldof the engine and a cylinder thereof, the block having a manifoldchannel therethrough, the manifold channel having an input end and anoutput end, wherein the input end communicates in use with the inletmanifold and the output end communicates in use with the cylinder, themanifold channel including at least one injector head channel locatedtowards the input end of the manifold and adapted to receive a fuelinjector, the manifold channel having a longitudinal axis and atransverse axis, said injector head channel being orientated withrespect to at least one of the longitudinal and transverse axes of themanifold channel at an angle of convergence from 5° to 85° such thatfuel injection into the manifold channel impinges against the manifoldchannel wall and adopts, by virtue of the convergence angle, a swirlingpath of motion through the manifold channel.
 2. A manifold blockaccording to claim 1 fitted between the inlet manifold and a cylinderhead of the engine, thereby increasing a distance between a fuelinjection point and the cylinder head of the engine.
 3. A manifold blockaccording to claim 1 arranged in the engine to facilitate turbulentmixing of the injected fuel in the manifold channel.
 4. A manifold blockaccording to claim 1 wherein an axis of the injector head channel andone of the axes of the manifold channel at a location of injectionconverge at an angle of convergence effective to facilitate swirlingmotion of a fuel/air mixture therein.
 5. A manifold block according toclaim 1 wherein the angle of convergence of the injector head channel isselected to cause the fuel injected into the manifold channel to adopt aswirling path of motion through the manifold channel independent of aswirling motion caused by impingement of the fuel against the manifoldchannel wall.
 6. A manifold block according to claim 1 wherein the angleof convergence of the injector head channel is with respect to thelongitudinal axis of the manifold channel.
 7. A manifold block accordingto claim 1 wherein the angle of convergence of the injector head channelis with respect to the transverse axis of the manifold.
 8. A manifoldblock according to claim 1 wherein the angle of convergence is fromabout 15° to about 75°.
 9. A manifold block according to claim 8 whereinthe angle of convergence is from about 20° to about 70°.
 10. A manifoldblock according to claim 9 wherein the angle of convergence is fromabout 20° to about 65°.
 11. A manifold block according to claim 10wherein the angle of convergence is from about 25° to about 60°.
 12. Amanifold block according to claim 1 wherein the injector head channel isupstream of the manifold channel in use of the block.
 13. A manifoldblock according to claim 1, wherein the manifold channel is arranged toreceive a perforated element which allows the passage of a fuel/airmixture there through, and means for mounting the perforated element inthe manifold channel.
 14. A manifold block according to claim 14 whereinthe manifold channel is further adapted to receive a propeller element,and means for mounting the propeller element in the manifold channel.15. A manifold block according to claim 15, wherein the perforatedelement and the propeller element are situated between the injector headchannel and the output end of the manifold channel.
 16. A manifold blockaccording to claim 16 wherein the propeller element is driven by amotor.
 17. A manifold block according to claim 1 connected to the engineblock of an internal combustion engine.
 18. A manifold block accordingto claim 1 wherein the manifold channel has a length so that in use ofthe block the inlet manifold and the cylinder are in spacedrelationship.
 19. A manifold block according to claim 18 wherein thechannel length in the block is at least about 1 cm.
 20. A manifold blockaccording to claim 1 wherein the manifold block is heated.